Zootaxa 1962: 33–48 (2008) ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ ZOOTAXA Copyright © 2008 · Magnolia Press ISSN 1175-5334 (online edition) Maluti Mystery: A systematic review of Amietia vertebralis (Hewitt, 1927) and Strongylopus hymenopus (Boulenger, 1920) (Anura: Pyxicephalidae) JEANNE TARRANT1,3, MICHAEL J. CUNNINGHAM2 & LOUIS H. DU PREEZ1 1School of Environmental Science & Development, Potchefstroom Campus, North-West University, Private Bag X6001, Potchefstroom 2520,South Africa. Email: [email protected] 2Department of Zoology,University of the Free State, Private Bag x 13, Phuthaditjhaba, 9866, South Africa. Email: [email protected] 3Corresponding author. E-mail: [email protected] Abstract The taxonomic status of Amietia vertebralis and Strongylopus hymenopus, two frogs restricted to the Maluti-Drakens- berg highlands in southern Africa, is unclear. Here, morphological examination and phylogenetic analyses elucidate the systematic position of these two species. Type specimens of both species were examined and compared with more recent collections to clarify their identity. These comparisons revealed discrepancies between the original application of these names and their current usage. The holotype and original description of A. vertebralis match specimens from an extant population at that species’ type locality that are currently assigned to S. hymenopus. Furthermore, the type specimen of S. hymenopus is of uncertain provenance and does not match well with either of the forms currently associated with these names. We assessed both intraspecific and interspecific variability using DNA sequence data. Broad sampling of the form currently assigned to A. vertebralis revealed very little genetic variation thereby dispelling the hypothesis that this is a compound taxon. The generic placement of both species within the family Pyxicephalidae was resolved using a com- bined dataset of mitochondrial 16S rDNA and nuclear RAG1 gene sequences. The form currently recognised as S. hymenopus was excluded from the otherwise monophyletic genus Strongylopus, and was placed instead within Amietia. Based on these data a revised application of both species names is recommended here. Populations currently assigned to Amietia vertebralis are referred to Amietia umbraculata and those attributed to Strongylopus hymenopus are referred instead to Amietia vertebralis. Key words: Amietia, Drakensberg, Lesotho, morphometrics, phylogenetics, Pyxicephalidae, South Africa, taxonomy Introduction The Aquatic River Frog, Amietia vertebralis (Hewitt, 1927) and the Berg Stream Frog, Strongylopus hymeno- pus (Boulenger, 1920) are two relatively poorly known high-altitude species with restricted ranges within the Maluti-Drakensberg Mountains and Lesotho highlands of southern Africa (Fig.1). This study demonstrates that the current usage of these scientific names is incorrect and identifies the correct names for these species. For clarity in presenting this argument, however, the current use of these names is maintained through the arti- cle, with inverted commas to show that these are names of convenience, subject to our nomenclatural conclu- sions. ‘Amietia vertebralis’ (non Hewitt) is a high-altitude montane species, recorded between 1680 – 3400 m above sea level, in most of the major rivers of Lesotho, as well as, historically, in the upper reaches of the Thukela and Mzimkulu rivers in KwaZulu-Natal, the Elands River in the Free State, and the Bell River in the Eastern Cape (Bates 2002). This species is mainly found in rivers that flow south-westward across Lesotho. ‘Strongylopus hymenopus’ (non Boulenger) is recorded at altitudes between 1800 – 3200m, and is restricted to Accepted by M. Vences: 30 Oct. 2008; published: 12 Dec. 2008 33.